>I think the main problem is that the increase in complexity (for the >characters themselves, let alone the person who has to manage >describing what they're doing) isn't linear. Dealing with three >characters in a relationship isn't twice as hard as two, it's more >like nine times as hard.

Yah, seriously.

I was actually in a polyamorous relationship for a while, and the thing that makes this even worse is, in real life nice tidy trios and foursomes are quite rare. What tends to happen is chains. Alice is dating Bob and Betsy, each of whom is dating two or three other people, and each of those people is dating a few more people, and so on; there are probably some loops back in there, but it's not unlikely that Alice hasn't even met all of the people at more than two removes from her -- but they can all potentially screw up her plans for the week.

It is very like the old joke about how green soldiers talk strategy but old soldiers talk logistics.